Natural bioactive peptides to beat exercise-induced fatigue: A review

Exercise-induced fatigue is charactered by the feeling of tiredness and a decrease in muscle performance resulting from intense and prolonged exercise. With the development of modern society, exercise-induced fatigue has become a widespread problem besetting people's daily life. Over the years, increasing attention has been paid to the study of anti-fatigue peptides. Several animal models have been developed to mimic exercise-induced fatigue, which could be employed to measure the activities of anti-fatigue peptides isolated from a wide range of sources. A number of natural bioactive peptides were identified with ability to prevent and alleviate exercise-induced fatigue via various complex biological reactions, with possible molecular mechanisms being also explored extensively. In this review, we summarize the major research findings on anti-fatigue peptides, including the isolation and preparation of anti-fatigue peptides, the widely adopted methods for evaluation of anti-fatigue activities, and possible anti-fatigue mechanisms. Current evidence strongly supports that anti-fatigue peptides may relieve exercise-induced fatigue via multiple mechanisms, including participation and regulation of energy metabolism; inhibition of inflammatory responses; reduction of reactive oxygen species content; and regulation of neurotransmitters, etc. In conclusion, the review provides key research perspectives to inform further research on anti-fatigue peptides for the food industry.